This invention relates to a hose coupler and, more particularly, to an improved coupler for attachment to a hose to provide a sealed conduit which is not susceptible to bacteria or other contaminants at the coupler connection. In the area of consumable bulk liquids, such as milk, consumable bulk powders and granular materials, such as dry powder milk, there is a need for minimizing the exposure of such bulk liquids, powders and granular materials to bacteria or other contaminants. The industry has relied upon a steel barbed coupler attached with compression straps for hoses in applications transporting this type of bulk product. Other coupler designs have included a piece which conforms to the hose's inner surface to aid in sealing and maintaining sanitary conditions.
Other attempts at providing a suitable sanitary coupler required vulcanizing the hose at the coupler/hose interface. Vulcanizing hardens the hose and eventually permits the capillary action between the hose and metal coupling. With this design, it was found if the hose was damaged, the entire unit had to be discarded. This proved to be quite costly and such couplers found little success in the industry. These types are still used in the industry; however, they are becoming less popular as users search for more sanitation. Internally expanded couplings begin in two parts: a "stem" and a "sleeve". To couple a hose, a sleeve is first placed over the hose's outer dimension. The assembly is then placed on a machine-driven tapered mandrel with die fingers capable of expanding. The stem is expanded into the inside diameter of the hose, thereby permanently compressing the rubber hose into the sleeve. These provided a somewhat suitable coupler for sanitary purposes, but, like the vulcanized coupler, were too costly because the coupler became part of the hose and had to be discarded upon damage.
A variety of other types of hose couplers exist which form a connection at the hose/coupler/hose or hose/coupler/coupler interfaces. One coupler type has a narrowing tapered threaded opening and creates threads on an end of a rigid pipe by forcing an end of the pipe into the threaded opening to create the connection. Another coupling type threads onto the end of a pre-threaded pipe. Loose tolerances in the couplers and hoses have thus far prevented a suitable fit and seal from being consistently achieved for sanitary communication of product through the hoses and couplers. The coupling devices have heretofor been complex and/or costly and, in many cases, inconvenient to use. At the present time there is a need for a coupling which is relatively simple to assemble, less costly, and provides a substantially sanitary seal. In addition, there is a need for a coupler which provides a sanitary seal at flexible hose ends when assembled, and which can be readily assembled and disassembled.